Inflammaging as the basis of age-associated diseases

Aging is one of the most complex biological phenomena that affects all human physiological systems, including the immune system. Immunosenescence is understood as structural and functional changes in both adaptive and innate immunity systems. The so-called inflammaging is among manifestations of immune aging. It is an age-related increase in inflammatory mediators and development of an inflammatory phenotype. An important role in development of inflammaging is assigned to chronic stimulation of immune system by exogenous and endogenous danger signals (pathogen-associated molecular pattern, PAMP and damage-associated molecular pattern, DAMP), which include viruses, microbiota of the gastrointestinal tract, free radicals, etc. PAMP and DAMP are recognized by the innate immunity system cells through the pattern recognition receptors (PRR), e.g., Toll-like receptors (TLR), RIG-I-like receptors (RLR), NODlike receptors (NLR), lectin receptors. Stimulation of PRR leads to activation of intracellular signaling and increased expression of pro-inflammatory factors. PAMPs are the most powerful activators of PRR and inflammation triggers; DAMPs can activate the same receptors and signaling pathways, causing the development of a sterile inflammatory response. The NF-kB signaling pathway is considered as a key signaling pathway for inflammaging. NLR stimulation also leads to formation of inflammasome. Its function is to transform the pro-inflammatory cytokines to a biologically active form, which is an important for the formation of a pro-inflammatory phenotype and development of inflammaging. This process is considered an important risk factor for morbidity and mortality among older people. Chronic inflammation underlies pathogenesis of many age-related diseases, such as osteoporosis, atherosclerosis, Alzheimer’s disease, Parkinson’s disease, type 2 diabetes. Various chronic diseases associated with age are directly related to PAMP and DAMP-induced TLR or NLRP3-mediated inflammatory response. Hence, these ligands and their receptors can be suggested as biomarkers and interventional targets for age-related disorders. Despite numerous studies in age-associated pathology, there are only few works on the contribution of innate immunity in healthy aging. It remains unclear whether the inflammatory phenotype is a manifestation of healthy aging, or it is associated with development of age-related pathology. Further study of the mechanisms of inflammatory aging will reveal biomarkers of healthy aging and potential targets for the treatment of age-associated diseases

Role of antimicrobial peptide DEFB126 mutation in pathogenesis of male idiopathic infertility

Male infertility is a multifactorial disease, and elucidation of etiopathogenetic mechanisms of its progression is a topical issue. High percentage of the “idiopathic infertility” diagnosis is largely cased by inability to establish etiology of decrease in reproductive spermatic function. Mutation of в-defensin DEFB126 gene is supposed to affect the fertilizing ability of spermatozoa at different levels: it may decrease their ability to migrate through the cervical mucus and reduce binding capacity to epithelial layer of upper female reproductive tract, and it may also increase susceptibility for infections of reproductive tract, due to impairment of local protective function of defensins. Thus, the aim of the present study was to examine possible role of rs11468374 gene polymorphism of the DEFB126 gene in pathogenesis of male idiopathic infertility. Patients and methods: The group of patient with decreased fertility included 54 male subjects, ages 34 to 42, with a control group of 19 ejaculate donors without acute or chronic disease aged 28 to 36. The indicators of sperm motility in the Moscow population were compared with individual levels of DEFB126 gene expression, as well as with estimated distribution frequency of rs11468374 alleles and genotypes among the subjects.As compared with the control group, the infertile patients exhibited a more than seven-fold reduction of DEFB126 gene expression. Analysis of distribution frequency for alleles and genotypes rs11468374 polymorphic marker of the DEFB126 gene revealed that the mutant allele is detected almost twice as often in males with infertility, as compared with control group. No cases with the DEFB126 del/del genotype were found among the control group, in contrary to 16.1% in the group of patients. The patients with DEFB126 del/del genotype exhibited 5.2-fold reduction of sperm motility. Thus, the data obtained may be used to extend our knowledge on the pathogenetic mechanisms of male idiopathic infertility and to improve techniques for its diagnostics, as well as to provide personalized approach to the treatment of male reproductive disorders. The association between carriage of del mutant allele and decreased level of sperm motility suggests a role of this polymorphism in pathogenesis of male infertility. A general decrease in the level of DEFB126 gene expression in the patients affected by infertility also presumes a contribution of defensin 126 to pathogenesis of the disorder

Phenotypic and functional changes of NK cells in patients with myelodysplastic syndrome and acute myeloid leukemia treated with hypomethylating drugs

Natural killer cells (NK cells) are cytotoxic lymphocytes that play a pivotal role in maintaining immunological surveillance and in developing an innate immune response. Since the discovery of NK cells in 1973, the mechanisms of their functioning have been studied in details, and there is currently no doubt that they play a special role in the process of recognition and destruction of transformed and malignant cells. Understanding the role of NK cells in antitumor immunity, on the one hand, leads to emergence of new immunotherapeutic strategies and, on the other hand, allows to adjust the existing treatment regimens for tumor diseases, in accordance with the principle of primum non nocere. Optimization of cancer therapy protocols executed in order to protect immune cells from death and functional impairment is an important problem that cannot be successfully resolved without regular aggregation of the results from disparate studies and critical analysis of the all accumulated data.The objective of this review is to create a relevant and holistic picture of changes in the phenotypic and functional characteristics of NK cells in patients with two related hematological diseases – myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). For the treatment of both illnesses, drugs from the group of hypomethylating agents are used, the acting mechanism of which, unlike classical cytostatic agents, is based on modulation of the tumor cell genes expression. All the cells of the body are being affected, including NK cells, since these drugs act nonspecifically. Such an interaction leads to a hypomethylation of NK cell DNA and changes the expression of functional receptors, which, in turn, provide the development of antitumor NK cell immune response.Of course, just the fact of changing gene expression in certain cells does not allow us to fully judge the drug’s impact on the state of immune system. Meanwhile, the origin of this change and its role are important in the context of the disease pathogenesis. Ultimately, a simple description of an increase or decrease in a single receptor expression is not illustrative, since it can lead to uncertain consequences. For this reason, the current review, in addition to describing the existing data on the changes of NK cell receptors expression under the influence of hypomethylating drugs, gives a special attention to critical analysis of functional characteristics of NK cells, including their cytotoxic activity aimed at malignant blast cells, being a determinant of clinical course in the described diseases

Role of cytokines in hepatocellular carcinoma

Liver cancer ranks No. 5 in the world among all types of cancer and takes 3rd position among cancer-related deaths. Hepatocellular carcinoma (HCC) is a primary malignancy which does not include liver metastases from other sites. It is the most common form of liver cancers, and one of the leading causes of cancer-related deaths worldwide. HCC includes genetically and morphologically heterogeneous group of malignant tumors. HCC is characterized by a gender predisposition, namely, it occurs in men 1.5-fold more often, than in women. Viral infections such as hepatitis B and C are major risk factors for HCC. Moreover, non-alcoholic steatohepatitis (NASH) associated with metabolic syndrome and type 2 diabetes also becomes an increasingly common risk factor in developed countries. The mechanisms underlying the development of HCC are based on genetic changes in tumor cells and their microenvironment. Recently, the role of changes in the tumor microenvironment has drawn more attention, thus becoming the key characteristic in the HCC pathogenesis at all stages of the malignant process. Hepatocytes have a close relationship with immune cells, since in the liver, in addition to hepatocytes, there are Kupffer cells, myeloid cells (dendritic cells, monocytes and neutrophils) and other types of immune cells (T and B lymphocytes, NK and NKT, etc.). Cytokines released by various immune cells in the liver may influence liver processes, e.g., inflammation and carcinogenesis. Chronic inflammation results from persistent stimulation, or deficiencies of anti-inflammatory mechanisms. Its key features include immune cell infiltration, presence of inflammatory mediators, and imbalance of pro- and antiinflammatory cytokines leading to aggressive angiogenesis and tissue remodeling which, in turn, promotes the malignant process. Currently, there are several approaches to the HCC treatment which depend on the stage of the disease. Immunotherapy and its combinations have shown positive advances, and further research in this area will provide therapeutic options at the terminal stages of HCC. A variety of cytokines and their functions in HCC development are discussed in the present review article

Mechanisms of innate immunity in pathogenesis of psoriasis: approaches to targeted therapy

Psoriasis is a chronic auto-inflammatory, genetically determined dermatosis, being multifactorial by origin, characterized by hyperproliferation of epidermis, affected keratinocyte differentiation and inflammatory reaction in dermis. The disease is characterized by a tendency to spread over the area of lesion, and involvement of articular tissue in the pathological process, which significantly affects the living standards of patients and causes their disability. There are many provoking factors that contribute to occurrence of psoriasis, or progression of existing psoriatic process in individuals with a genetic predisposition. These factors include adverse climatic conditions, skin trauma, exposure to ultraviolet light, burns, infections, etc.This review describes the role of innate immunity in pathogenesis of psoriasis, and describes in detail the mechanisms involved into induction of inflammation of PAMPs and DAMPs. In psoriasis, positively charged catelicidin is considered one of the most important DAMPs, which can form a complex with negatively charged cell polyanions-LL-37/auto-RNA and LL-37/auto-DNA. The interaction of PAMP/DAMP ligands with specific PRR receptors leads to signal activation of effector components of immune system, i.e., assembly of inflammasome complex, caspase activation, synthesis of inflammatory cytokines and processing of their immature forms. The review focuses on the role of TLRs under the conditions of physiological norm, which recognize danger signals and provide protection from pathogens and their timely elimination, and in development of pathological process. Activation of TLRs induces the production of pro-inflammatory cytokines, interferons and antimicrobial peptides, chemokines that support the development of psoriatic inflammation.In addition to TLRs, the mechanisms of involvement of inflammasomes in the development of psoriasis, which provides processing of mature forms of IL-1β and IL-18, are described in detail. Mature forms of these cytokines mediate the development of inflammation in psoriatic focus. In addition, processing of these cytokines by caspases using the positive feedback mechanism provides an additional signal to activate transcriptional activity of their genes and contributes to perpetuated inflammation.The review presents data confirming participation of inflammasomes in the pathogenesis of psoriasis. Much attention is paid to description of pharmacological inhibitors of inflammasomes, which in the future may be the drugs of choice for treatment of inflammatory diseases. The study of molecular mechanisms of the innate immune system will reveal new approaches to prognosis and development of targeted therapy for psoriasis

СHANGES OF TLR GENE EXPRESSION IN CERVICAL EPITHELIUM FROM THE PATIENTS WITH UROGENITAL INFLAMMATORY DISEASES

Toll-like receptors (TLR) are involved into innate immune recognition of microorganisms, including pathogenic bacteria. The aim of this work is to assess relative levels of TLR2 and TLR9 expression in cervical epithelial cells of women with inflammatory diseases of pelvic organs. The total group of patients consisted of 47 persons, including 20 women with urogenital infections, and 27 women comprised a control group. Using real-time PCR, we identified the opportunistic pathogens and gene expression levels of TLR2, TLR9 in the cervix epithelial cells. It was shown that expression of TLR9 in the group with urogenital infections was 13.7-fold higher than in control group. We have revealed that a significant increase of TLR9 expression in the mucosal epithelium from cervical canal correlated with detection of infectious pathogens in the samples

STUDY OF EXPRESSION OF HBD-1 AND HBD-2 GENES IN EPITHELIAL CELLS OF MUCOUS UPPER AIRWAY IN NEWBORNS WITH PNEUMONIA DEPENDING ON THE CAUSATIVE AGENT

Β-defensins play an important role in protecting the fetus from infection, so the expression of these antimicrobial peptides in the respiratory tract in newborns is really important. In this regard, we set a task of studying the expression of the HBD-1 and HBD-2 genes in the epithelial cells of the mucous of the upper airway in newborns with pneumonia and in healthy newborns, depending on the causative agent. Also, the polymorphic marker G(-20) A in the DEFB1 gene was associated with infectious pathology of newborns (in particular pneumonia). Methods: The microflora and the factors of congenital immunity on the mucous membranes of the upper airway have been studied in two groups: newborns with ventilator-associated and congenital pneumonia. The biological material was scrapings of epithelial cells of the mucous membrane of the upper airway of newborns and puerperas and blood. Results: It was found that the expression of the HBD-2 gene increases 2.3-fold in children who have an infectious agent, but there are no clinical manifestations of pneumonia. A significant decrease in HBD-2 (3.2 times) in patients with pneumonia caused by K. pneumonia was shown. The frequencies of alleles of the DEFB1 gene in the fetal infection group and in the comparison group: allele G - 0.66, 0.79, allele A - 0.34, 0.21, respectively. The frequencies of the genotypes of the test marker in mothers in the ventilator-associated, congenital pneumonia and the comparison group were as follows: GG - 0.78, 0.58, 0.58; AA is 0, 0.25, 0; AG - 0.22, 0.17, 0.42, respectively. In newborns allele G dominated among alleles (frequency was higher than 0.73 in all groups) and genotype GG (frequency exceeded 0.52). Conclusion: In the course of the study, it was confirmed that β-defensins protect the mucous from infectious agents. The results indicate that the genetic marker G (-20) A of the DEFB1 gene is associated with the risk of developing the child's UTI

Hyperexpression of TLR2 and TLR4 in patients with ischemic stroke in acute period of the disease

Pathogenesis of ischemic stroke  is actively  involved  in the  system  of innate immunity. Under conditions of cerebral  ischemia, a number of biologically  active  substances are  released  that  interact with innate immunity receptors, in particular TLR2  and  TLR4, which  exacerbate inflammation in brain  tissue. Identification of predictor markers  at the level of the innate immunity system may foresee the clinical course of ischemic stroke and ensure timely treatment. Our objective was to study expression of TLR2 and TLR4 receptors in peripheral blood leukocytes  in patients with ischemic stroke in the dynamics of the disease. 27 people  were included in the study. The main  group consisted of patients with ischemic stroke of varying severity (n = 19). Patients of the main  group were divided into two subgroups:  with an NIHSS index value of < 10 (n = 10) and > 10 (n = 9). The control group included healthy  donors  with no history  of acute  and chronic inflammatory diseases (n = 8). Peripheral blood  leukocytes  were used as the  test material. To determine expression  of the TLR2  and TLR4  genes, RT-PCR in real time was used. Surface  expression  of TLRs was determined by flow cytometry. A study of the TLR2 and TLR4 gene expression showed that on the 1st, 3rd  and 7th  day post-stroke, the TLR4 gene expression  in patients was significantly  increased, when compared to the control group (p < 0.01), whereas TLR2 gene expression on the 3rd  day of the disease was not statistically different from the control group. A study of surface expression  of receptors showed that the average TLR2 fluorescence intensity on the patients’ peripheral blood monocytes was significantly  increased on the 1st  and 3rd  day of disease when compared to the control group.  The  surface  expression  of TLR4  on monocytes has a statistically significant  increase  only on day 7. Assessment  of surface expression  of TLRs in subgroups  with different  severity values by NIHSS showed that  patients with a NIHSS index > 10 had a significantly  higher  level of surface of TLR2  expression  over the observation period, while the largest difference in TLR4  expression  in the subgroups  was observed  on the 1st day of the disease (p < 0.05). Patients with ischemic stroke showed an increase  in TLR2 and TLR4 expression at the gene and protein level, compared to healthy  donors. These indices can be considered possible predictors for clinical  prognosis  of ischemic stroke

CHANGES OF INNATE IMMUNITY INDEXES IN SEVERE ASTHMA IN CHILDREN

At the present time, the role of innate immunity in pathogenesis of bronchial asthma (BA) is actively studied, in particular, significance of TLRs and cytokines. The study included 42 patients with severe bronchial asthma (from 3 to 12 years old), and 67 healthy children at the same age. Expression of TLR2, TLR4, and TLR9 genes was evaluated by PCR-RT from the scrapings of nasal mucosa; cytokines (IL-33, TSLP, IL-4, TGF-β1 and IL-28B) were assayed in nasal swabs by ELISA technique. The main results were as follows: an increased gene expression of TLR2, TLR4, TLR9 genes was revealed in the nasal mucosa scraps from the patients with bronchial asthma as compared to healthy children. We have also measured the contents of important cytokines secreted by the respiratory epithelium in the course of TLRs activation. The study of IL-33, TSLP, IL-4 in nasal samples revealed significantly increased concentrations of these cytokines in the patients with severe BA against the control group. A study of TGF-βlevels in nasal cavity swabs revealed a significant decrease of this regulatory cytokine in the group of pediatric patients with asthma. Worth of note, evaluation of antiviral IL-28B cytokine in the group of patients with severe BA showed a significant downward trend, in comparison to the control indexes. Hence, one may conclude on some disturbances of local innate immunity system in the patients with severe BA which manifest as hyperexpression of TLRs genes, increased production of proinflammatory and epithelial cytokines, decreased production of antiviral IL-28B cytokine, and TGF-β1

Genetic diagnostic criteria for periodontitis

The article assesses the results of the determination of gene polymorphism DEF-44, DEF-20, IL-10, TNF, TLR2_753, TLR2_677 in patients with chronic generalized periodontitis. The correlation presence of ENT diseases and the emergence of periodontal disease with a high probability of gene polymorphism DEF-44 and TLR-2.В статье проводится оценка результатов определения полиморфизма генов DEF-44, DEF-20, IL-10, TNF, TLR2.753, TLR2_677 у пациентов, больных хроническим генерализованным пародонтитом. Определена взаимосвязь наличия ЛОР патологии и возникновения заболеваний пародонта при высокой вероятности полиморфизма генов DEF-44 и TLR-2